import { protectedFetch } from "./api.js?v=__ASSET_VERSION__";
import { initSideNav, loadNavUser } from "./nav.js?v=__ASSET_VERSION__";
import { ACADEMY_TRACKS } from "./academy-content.js?v=__ASSET_VERSION__";
import { SCENES, sceneDefs, sceneFallbackText } from "./academy-scenes.js?v=__ASSET_VERSION__";

// ── Progress ───────────────────────────────────────────────────────────────

const PROGRESS_KEY = "academyProgress.v1";
function loadProgress() {
	try {
		return JSON.parse(localStorage.getItem(PROGRESS_KEY)) ?? {};
	} catch {
		return {};
	}
}
function saveProgress(lessonId, patch) {
	const all = loadProgress();
	all[lessonId] = { ...all[lessonId], ...patch };
	try {
		localStorage.setItem(PROGRESS_KEY, JSON.stringify(all));
	} catch {
		/* storage unavailable */
	}
}

// ── Player ─────────────────────────────────────────────────────────────────

let current = null; // {track, lesson, index}
const audio = new Audio();
let autoplay = true;

const $ = (id) => document.getElementById(id);

function renderMenu() {
	const progress = loadProgress();
	const mount = $("academy-menu");
	mount.replaceChildren(
		...ACADEMY_TRACKS.map((track) => {
			const wrap = document.createElement("section");
			wrap.className = "panel-card";
			const head = document.createElement("div");
			head.className = "panel-head";
			const h2 = document.createElement("h2");
			h2.textContent = track.name;
			head.append(h2);
			const body = document.createElement("div");
			body.className = "panel-body";
			const blurb = document.createElement("p");
			blurb.className = "muted";
			blurb.style.marginTop = "0";
			blurb.textContent = track.blurb;
			body.append(blurb);
			const list = document.createElement("div");
			list.className = "academy-lessons";
			track.lessons.forEach((lesson, li) => {
				const state = progress[lesson.id] ?? {};
				const resumeAt = state.done ? 0 : (state.slide ?? 0);
				const btn = document.createElement("button");
				btn.type = "button";
				btn.className = "academy-lesson";
				const num = document.createElement("span");
				num.className = "academy-lesson-num";
				num.textContent = state.done ? "✓" : String(li + 1);
				if (state.done) num.classList.add("done");
				const mid = document.createElement("span");
				mid.className = "academy-lesson-mid";
				const label = document.createElement("span");
				label.className = "academy-lesson-label";
				label.textContent = lesson.title;
				const meta = document.createElement("span");
				meta.className = "academy-lesson-meta";
				meta.textContent = state.done
					? `completed · ${lesson.slides.length} slides · ~${lesson.minutes} min`
					: resumeAt > 0
						? `resume at slide ${resumeAt + 1} of ${lesson.slides.length}`
						: `${lesson.slides.length} slides · ~${lesson.minutes} min`;
				const bar = document.createElement("span");
				bar.className = "academy-progress";
				const fill = document.createElement("span");
				fill.className = "academy-progress-fill";
				fill.style.width = state.done
					? "100%"
					: `${Math.round((resumeAt / lesson.slides.length) * 100)}%`;
				bar.append(fill);
				mid.append(label, meta, bar);
				btn.append(num, mid);
				btn.addEventListener("click", () => openLesson(track, lesson, resumeAt));
				list.append(btn);
			});
			body.append(list);
			wrap.append(head, body);
			return wrap;
		}),
	);
}

function openLesson(track, lesson, index) {
	current = { track, lesson, index };
	$("academy-menu").classList.add("hidden");
	$("academy-films")?.classList.add("hidden");
	// Pause any playing film so it doesn't run (and download) behind the lesson.
	for (const video of document.querySelectorAll("#academy-films video")) video.pause();
	$("academy-player").classList.remove("hidden");
	renderSlide();
}

function closeLesson() {
	audio.pause();
	current = null;
	$("academy-player").classList.add("hidden");
	$("academy-menu").classList.remove("hidden");
	$("academy-films")?.classList.remove("hidden");
	renderMenu(); // reflect fresh progress
}

function renderSlide() {
	const { lesson, index, track } = current;
	const slide = lesson.slides[index];
	saveProgress(lesson.id, { slide: index });
	$("player-lesson").textContent = `${track.name} — ${lesson.title}`;
	$("player-slide-title").textContent = slide.title;
	$("player-count").textContent = `${index + 1} / ${lesson.slides.length}`;

	// Rebuilt per slide so CSS animations restart with it.
	const svg = $("player-scene");
	svg.replaceChildren(sceneDefs());
	try {
		svg.append(...SCENES[slide.scene[0]](slide.scene[1] ?? {}));
	} catch {
		svg.append(sceneFallbackText(slide.title));
	}

	$("player-caption").textContent = slide.transcript;

	const dots = $("player-dots");
	dots.replaceChildren(
		...lesson.slides.map((s, i) => {
			const dot = document.createElement("button");
			dot.type = "button";
			dot.className = `academy-dot${i === index ? " active" : ""}`;
			dot.setAttribute("aria-label", `Slide ${i + 1}: ${s.title}`);
			dot.addEventListener("click", () => {
				current.index = i;
				renderSlide();
			});
			return dot;
		}),
	);
	$("player-prev").disabled = index === 0;
	$("player-next").textContent =
		index === lesson.slides.length - 1 ? "Finish lesson" : "Next →";

	audio.src = `/academy-audio/${slide.id}.mp3?v=__ASSET_VERSION__`;
	if (autoplay) audio.play().catch(() => setPlayState(false));
	setPlayState(autoplay);
}

function setPlayState(playing) {
	$("player-play").textContent = playing ? "❚❚" : "▶";
	$("player-play").setAttribute("aria-label", playing ? "Pause narration" : "Play narration");
}

function next() {
	const { lesson, index } = current;
	if (index >= lesson.slides.length - 1) {
		saveProgress(lesson.id, { done: true, slide: 0 });
		closeLesson();
		return;
	}
	current.index++;
	renderSlide();
}

function wirePlayer() {
	$("player-close").addEventListener("click", closeLesson);
	$("player-prev").addEventListener("click", () => {
		if (current.index > 0) {
			current.index--;
			renderSlide();
		}
	});
	$("player-next").addEventListener("click", next);
	$("player-play").addEventListener("click", () => {
		if (audio.paused) {
			autoplay = true;
			audio.play().catch(() => {});
			setPlayState(true);
		} else {
			audio.pause();
			setPlayState(false);
		}
	});
	audio.addEventListener("ended", () => {
		setPlayState(false);
		// Give the animation a beat, then advance — hands-free lesson flow.
		if (autoplay && current) setTimeout(() => current && next(), 1200);
	});
	document.addEventListener("keydown", (event) => {
		if (!current) return;
		if (event.key === "ArrowRight") next();
		if (event.key === "ArrowLeft" && current.index > 0) {
			current.index--;
			renderSlide();
		}
		if (event.key === "Escape") closeLesson();
		if (event.key === " " && event.target === document.body) {
			event.preventDefault();
			$("player-play").click();
		}
	});
}

document.getElementById("btn-logout").addEventListener("click", async () => {
	await protectedFetch("/api/auth/logout", { method: "POST" });
	location.assign("/");
});

async function init() {
	initSideNav();
	const user = await loadNavUser();
	if (!user) return;
	renderMenu();
	wirePlayer();
}

init();